Push-button electric switch



E. F. MEKELBURG PUSH BUTTON ELECTRIC SWITCH Nov. 22, 1949 2 Sheets-Sheet 1 m% M n Filed March 29, 1946 E. F. MEKELBURG PUSH BUTTON ELECTRIC SWITCH Nov. 22, 1949 2 Sheets-Sheet 2 Filed March 29, 1946 L H z M 9/ N 7 Z Patented Nov. 22, 1949 PUSH-BUTTON ELECTRIC SWITCH Earl F. Mekelburg, Wauwatosa, Wis., assignor to Square D Company, Detroit, Mich., a corporation of Michigan Application March 29, 1946, Serial No. 658,284

7 Claims.

This invention relates to a push button operator for electric switches in which the switching operation is effected by rectilinear movement of the operating member.

Certain features of the push button operator including the rotary selector are claimed in applicants divisional application, Serial No. 77,489 filed February 21, 1949.

An object of the invention is the provision of an improved liquid seal for electric switch push button operators.

Another object of the invention is the provision of a push button operator for electric switches having improved means for sealing against entrance of liquid through the moving parts and for drainage of liquid entering at the push button.

Other objects and features of the invention will be readily apparent to those skilled in the art from the specification and appended drawings illustrating certain preferred embodiments in which:

Figure 1 is a front elevational view of a push button operator for electric switches according to the present invention.

Figure 2 is a sectional view on the line IIII of Figure 1 showing the electric switch and the operator mounted in a panel.

Figure 3 is a detail sectional view on the line IIIIII of Figure 2.

Figure 4 is a detail sectional view on the line IV-IV of Figure 3.

Figure 5 is a partial view similar to Figure 2 but showing the parts with the rotary selector in its second position.

Figure 6 is an enlarged detail sectional view on the line VI-VI of Figure 1.

Figure '7 is a detail sectional view on the line VII-VII of Figure 5.

Figure 8 is a sectional view on the line VIII- VIII of Figure 5.

Figure 9 is a diagrammatic representation of the operation of the electric switch in difierent positions of the rotary selector.

The push button electric switch according to the present invention, as specifically illustrated in the drawings, comprises a main body portion I having a rear flange 2 and a rear generally cup-shaped opening 3. The operator and switch are shown in Figures 2 and 5 in their operating position mounted upon a sheet metal panel 4 with the main body portion l of the operator extending through a circular opening in the panel. Between the flange 2 and the panel 4 is disposed a sealing gasket 5 preventing the entrance of liquid through the panel opening. A pin 6 disposed in the flange 2 extends into a recess in the back of the panel 4 to locate the operator and prevent rotation of its main body portion.

Extending from the front of the main body portion I is a hollow hub l of substantial length to provide an elongated sliding and rotating hearing for the stem 8 of an operating push button 9. At the interior end of the stem 8 is mounted an operating disc II supported on the stem by a stud passing through a hub I3 keyed against rotation on an extension I4 of the stem 8. In front of the main body portion I is mounted a generally cup-shaped guard I5 within which the push button 9 is recipro-cable. The guard I5 is rotatable about the hub I and is maintained in position by a sleeve I6 pressed on the exterior surface of the hub I. A flanged, cup-shaped member I'I surrounds the hub l and sleeve I6 and is provided at its interior end with a packing gasket I8. A spring I9 is disposed between the flange on the member I1 and the interior surface of the hub of push button 9 and serves not only to bias the push button 9 outwardly, but also to compress the packing gasket I8 into tight engagement with the surface of the stem 8 and the forwardly facing surface of the hub I to render the sealing more effective.

On the front face of the panel is disposed an indicator plate 2| and in front of the indicator plate is a clamping ring 22 threaded on the main body portion I of the operator and clamping against the nameplate 2| and panel 4 to mount the switch and operator in position to ensure the effectiveness of the gasket 5. The guard I5 about its periphery is provided with a plurality of drain slots 0r openings 23 communicating with the space 24 within the clamping ring 22 and the periphery of the clamping ring 22 is provided with a plurality of drainage slots or openings 25 communicating withthe exterior.

Within the opening 3 in the main body portion I are disposed a pair of integral cam members 26 and 21 having inclined surfaces 28 and 29. The operating disc II is provided with a plurality of cam elements 3| positioned to cooperate with the cam members 26 and 21 when rotated thereagainst to effect inward movement of the disc I I.

The electric switch proper is shown in elevation at 32 since the detailed operating structure thereof forms no part of the present invention. As indicated diagrammatically in Figure 9, the

switch is comprised of two double throw switches independently operable. Such switches are conventional and the switch 32 may take any desired form with rectilinearly movable operating members. These operating members are illustrated at 33 and 34 in the drawing and are reciprocable in the conventional manner to effect disengagement of one set of contacts and engagement of the other set of contacts of each 01' the switches, the operators 33 and 34 being interiorly biased toward their extended position. The flange 2 is provided with a plurality of hubs 33 threaded to receive screws 36 to mount the switch proper in alternate positions at the rear of and upon the main body portion I of the operator.

The operating disc ii is provided with a slot 31 of a size to permit passage therethrough 01' the push button operating member 33 and is disposed in front of the operator 33 in one of the two operating positions of the disc i i and guard l3. Within the cam members 25 and 27 are disposed springs 33 and balls 33, with the balls 39 received in suitable recesses in the back face of the guard l to index it into these two operating positions. The guard I5 is provided with an integral key 4i on its interior surface cooperating with a slot 42 in the push button 9 to ensure rotation of the push button with rotation of the guard l5 while permitting reciprocatory movement of the push button 9 relative to the guard. The cup-shaped guard i5 is cut away as at 43 over one-half of its periphery to facilitate the depression of the push button 8 without the necessity of asserting the operators digit within the guard.

In the operation of the push button electric switch according to the present invention, the operation of the contacts of switch 32 upon movement of the push button 3 is controlled by the position of the guard II. In position I, corresponding to the illustrations in Figures 1 and 2, depression of the push button 9 will move the operating disc H inwardly to move the switch operator 34 to first open the normally closed contacts and thereafter close the normally open contacts diagrammatically shown in Figure 9. During this operation, the slot 31 will pass about the operator 33 without effecting movement thereof. Upon release of the push button 3, the contacts of the switch having operator 34 will return to their initial position under their internal bias and with the push button movement assisting by the spring l3.

When the guard i3 is rotated into its second position, the cam elements 3i on the operating disc Ii engage the cam members 26 and 21 within the opening 3 of the main body portion I and will ride to the surface thereof to move the disc ll inwardly into the position shown in Figure 5. As the slot 31 is no longer in front of the operator 33, this movement inwardly of disc il effects movement of both the operators 33 and 34 to disengage the normally closed contacts of both switches as shown in full lines in the diagrammatic position 2 of Figure 9. Depression of the push button 9 with the guard II in the position of Figure 5 thereafter eilects closing of the normally open contacts of both of the switches, since the disc I i moves both of the operators 33 and 34. Release of the push button I thereafter returns the movable contacts to the intermediate position shown in full lines in the position 2 illustration of Figure 9. To return the contacts of the switches to the position with the normally closed contacts engaged, the guard II is rotated back to its initial position whereupon the parts return to the position shown in Figure 2.

It will be understood that while the switch 32 had been diagrammatically shown in Figure 9 as comprising a pair of double throw switches. each having normally open and normally closed contacts, that any combination of switching contacts, single or double throw and normally open or normally closed, are contemplated within the scope of the invention, since a myriad of cornbinations may be evolved for the various circuit arrangements desired. Also, while th slot 31 has been shown as receiving the operator 33 in only one position of the rotary selector guard I5, this slot may be made of any length and combined with any desired number of positions of the rotary selector guard to cooperate with any of the desired switching combinations which may be used with the operator to effect the desired circuit controls.

In the sealing feature of applicant's push button operator, any liquid such as oil, coolant, or cutting compound which may enter between the push button 9 and the guard I5 is immediately drained through the openings 23 in the guard i5 and the openings 25 in the clamping ring 22 to the exterior of the operator. These liquids are prevented from entering through the panel opening by the gasket 5. The packing gasket 18, effectively pressed against stem 8 and the hub I under the action of the compression spring I9, prevents entrance of the liquid between the stem 8 and the bearing in the hub i. This sealing construction of the operator not only effectively prevents entrance of any liquid entering the guard, but immediately drains off to the exterior any liquid which so enters. The lon hub i not only assures smooth operation, but by extending a substantial distance in front of the surface of the guard aids in the seal in preventing an accumulation of liquid at the packing [8. It will, of course, be understood that while the sealing and drainage feature has been shown in connection with a rotary selector guard, this is of general application and may, with equal effectiveness, be utilized with stationary guards Where th push button has a simple reciprocatory movement.

While certain preferred embodiments of the invention have been specifically disclosed, it is understood that the invention is not limited thereto, as many variations will be readily apparent to those skilled in the art and the invention is to be given its broadest possible interpretation within the terms of the following claims.

What is claimed is:

1. A push button operator for electric switches comprising a main body portion having a bearing therein, an operating push button having a stem passing through said bearing, a guard about said push button, a seal preventing passage of liquid between said stem and bearing, and drainage openings in said guard for venting liquid entering therein about said push button.

2. A push button operator for electric switches comprising a main body portion having a bearing therein, an operating push button having a, stem passing through said bearing, a guard about said push button, a seal preventing passage of liquid between said stem and bearing and drainage openings in said guard for venting liquid entering therein about said push button, said bearing extending a substantial distance forwardly of said drainage openings to prevent the accumulation of liquid at the seal.

3. A push button operator for electric switches comprising a main body portion adapted to be inserted through a panel opening, a bearing in said main body portion, a push button having a stem extending through said bearing, a guard shield about said push button, a clamping ring for clamping said body portion to a panel in which it is mounted, a plurality of drainage openings in the wall of the guard leading to the interior of said clamping ring and a plurality of drainage openings serving to vent any liquid entering the shield around the push button.

4. A push button operator for electric switches comprising a main body portion adapted to be inserted through a panel opening, a bearing in said main body portion, a push button having a stem extending through said bearing, a, seal preventing passage of liquid through the bearing about said stem, a guard about said push button, a clamping ring for clamping said body portion to a panel in which it is mounted, a plurality of drainage openings in the wall of the guard leading to the interior of said clamping ring and a plurality of drainage openings in the wall of the clamping ring leading to the exterior, said drainage openings serving to vent any liquid entering the shield around the push button.

5. A push button operator for electric switches comprising a stationary portion, a bearing in said stationary portion, an operating push button having a stem passing through said bearing, a seal between said stem and bearing preventing the passage of liquid therethrough, and a spring loading said seal to increase its effectiveness, said spring also biasing said push button to its nonoperated position.

6. A push button operator for electric switches comprising a stationary portion, a bearing in said stationary portion, an operating push button having a stem passing through said bearing, a packing disposed about said stem and against the end of said bearing, a cup-shaped member disposed about said packing and having an opening in its base receiving said stem, and spring means disposed between said push button and said cupshaped member to increase the effectiveness of the seal afforded by said packing and also to bias said push button to its non-operated position.

7. A push button operator for electric switches comprising a stationary portion adapted to be mounted in a supporting panel, a bearing in said stationary portion, an operating push button having a stem passing through said bearing, a seal between said stem and bearing preventing the passage of liquid therethrough, and a spring loading said seal to increase its effectiveness, said spring also biasing said push button to its nonoperated position, a guard shield disposed about said push button and stem, a clamping ring for securing said main body portion in its panel mounting, and drainage openings through the walls of said guard shield and clamping ring for venting liquid entering the shield.

EARL F. MEKELBURG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,200,460 Booraem Oct. 10, 1916 1,323,716 Nelson Dec. 2, 1919 1,636,347 Woodroot July 19, 1927 2,149,226 Merkel Feb. 28, 1939 2,202,207 Johnson May 28, 1940 2,357,973 Robbins Sept. 12, 1944 

